hi, ive just been reading through this website on differentiation, anyway ive just come across subtraction and addition of functions, KryssTal : Introduction to Calculus theres the link, if you scroll down about 1/4 of the way down you will see the section i am talking about, can anyone explain this a bit easier i cant seem to grasp the concept, especially when i was following an example; (i) For the function y = 4x2 + 2x + 3, the derivative is dy/dx = 8x + 2 now i cant see where the 2 has come from, i get the 8x part but not the second bit.
please help.

Apr 22nd 2010, 04:32 AM

Dint

Hi,

if you know that for

think about

here a = 5 and n = 1

now do the substitution with the formula I gave you...

Apr 22nd 2010, 04:34 AM

craig

Is this you first your first experience with Calculus?

To differentiate basic functions such as the one above, you multiply the coefficient by the power, and then reduce the power by one.

For example:

The derivative of is

As for the second bit:

, so differentiating this gives you .

Hope this clear is up a bit. A great place to check out if you want to learn the basics of calculus is Khan Academy on Youtube.